Some people stocked up back in the days before $4 gallon gas. Oil prices havent come down since then.
However, I have it at my Auto Zone. 0w30 Syntec that has "Made in Germany" in little tiny print on the back of the bottle.
Last time I checked it was 6.99 a quart.
What kind of car do you have? Castrol Edge 5W-30 is probably just as good if not better unless you need European engine certification (certain BMW, Mercedes, VW, etc).
Don't bother asking the counter clerks, they generally have no idea what 'German Castrol' is.
You'll have to go back there and look for 0W-30 for yourself.